Functional tricuspid regurgitation (FTR) is governed by several pathophysiologic abnormalities such as tricuspid valve annular dilatation, annular shape abnormality, pulmonary hypertension, left or right ventricle dysfunction, right ventricle geometry, and leaflet tethering. Treatment options for FTR are primarily surgical. The current prevalence of moderate-to-severe tricuspid regurgitation is estimated to be 1.6 million in the United States. Of these, only 8,000 patients undergo tricuspid valve surgeries annually, most of them in conjunction with left heart valve surgeries.
Ischemic heart disease causes mitral regurgitation by the combination of ischemic dysfunction of the papillary muscles, and the dilatation of the left ventricle that is present in ischemic heart disease, with the subsequent displacement of the papillary muscles and the dilatation of the mitral valve annulus.
Dilation of the annulus of the mitral valve prevents the valve leaflets from fully coapting when the valve is closed. Mitral regurgitation of blood from the left ventricle into the left atrium results in increased total stroke volume and decreased cardiac output, and ultimate weakening of the left ventricle secondary to a volume overload and a pressure overload of the left atrium.
It has been reported that at least 30% of patients that suffer from mitral valve regurgitation have concurrent regurgitation of the tricuspid valve. See, for example, Di Mauro et al., “Mitral Valve surgery for functional mitral regurgitation: prognostic role of tricuspid regurgitation,” European Journal of Cardio-thoratic Surgery (2009) 635-640, and King R M et al., “Surgery for tricuspid regurgitation late after mitral valve replacement,” Circulation 1984; 70: I193-7.